Train-control device



Een, 4, 3928;

C. A. NELSON TRAIN CONTROL DEVICE Filed April 20, 1927 wml B1 In!! Figlia!! flight All atented ec.k d, lg,

Honss- AIR BRAKE COMPANY, or Wimananrive, 'PENNSYLVANIA, A ooRroRArIon OF PENNSYLVANIA.

` 'IHREN-CONTROL DEVCE.

Application lcd April 20,' 1927.. Serial H0. 185,150.

speed signal indication. i/Vhen thetrain is operating in territory governed by a high speedr signalmdication andthe train control apparatus operates to make a brake application, the split reduction means isantomatically out out 'and a continuous 'full reduction in Y brake pipe pressure is automatically ellected; rlhe'spht reduction means, above referred to, is controlled by aout-out portion, having a p`iston,which in turn is governed by the medium speed application valve in thefspeed governor. iliVhen the speed of the train is below7 the `mediumspeed limit, andthe medium4 speed valve `is closed, linid under pressure eqnalizes on the opposite sides ot' the cut-ontA piston through a port in the piston and'said piston is then held in the split reduction-position by Va spring,fbut xvlienthe speed of the train is above the medium speed limit and the medium speed valve' is opened', the cut-out piston-chamber is vented to the atmospliere past the medium speed valve and the split reduction cut-out piston is shifted to the cut-ont position.v In this position, fluid underpref'- sure'continuously-lions throughthe port in the cntoiit piston and-thence to the atmosphere through the opened medium Vspeed Valve,so long as the medium speed application valve remains open. Y

The principal object 01"' my invention-is to provide an improved control means for the split reductiony cut-outportion of the train control apparatnsabove referred to, in "which, liowA ot i'luid to the atmosphere, when the medinmspeed valve is opened, is prevented,

except when the train kcontrol apparatus functions brakes. f

ln the accompanying drawing,

trol apparatus embodying my invention.

to Vetlect an application 'ot the" the single iie'nre is a diagrammatic lviewot a train con@ D ZD train control apparatus is substantially the saine as that of the` pending application, above referred to,` thc same ivill not be described in detail herein, but only to the extent deemed necess y to a Yfull understanding ot the invention.

The apparatus shoivn on the drawing includes an application valve device l, a pilot valve device 2, valve devices 18 and 19 for ei:- ecting a braiie pipe reduction in two stages, a split reduction cnt-ont device l, a speed governor 5 and a plurality oi' valves adapted to be operated by the speed governor. y

The application valve device l comprises a casing having arpiston chamber 6 contain` ing a piston Y and a valve chamber 8 containing a "de valve 9, adapted to be operated by said piston.

The pilot va ve device 2 comprises acasing having a piston chamber l0, containing a piston ll and a slide valve chamber l2 containing a slide valve 13, said slide valve having a cavity la adapted, in the rearward or release position oit the slide valveV to connect passage l5 '.tromthe application valve piston chamber 6 to passage 16 from the application valve slide valve chamber 8, and-in the forward or application position of the slide valve cavity il connects 'passage l'to an atmospheric ei:- haust passage 117s The means for effectingduction in two valve device i9,

a brake pipe -restades comprises a control controlled by the fluid vented from the brake pipein effecting a brake pipe i redaction, ahold baclr valve device if) and a rednction ensuring valve device 20.

prises a casing having pistfnichamber l containing` a piston 22 and a valve chamber c3 containing a slide valve 2%, adapted to be operated by said piston. The slide valve 24 has a cavity 25, which', ivith the piston in theV position shown in the drawing, connects pas- 26, from the first 'redaction reservoir' 27,'to passage 2S from the second reduction reservoir 29. lllhen the cut-out piston 22 and slide valve fiel are in the opposite or down` Ward position, the passages 26 and Q8 are disconnected and lappedb'y thev slide valve.

The speed governor is oi' the usualy centrifugal type,`adapted"to be rotated accordi ing to the speed of the is adapted to cause a movement ot a push rod 3i. Mounted on the outer end of the push rod the split reduction .eut-out device Ll comtrain and in operation,

is a crosshead 3Q, carrying a plurality of adjustable ta-ppet stems adapted to operate corresponding valves at various train speeds, including a medium speed application valve 33, which is unseated at and above the medium speed limit. The medium speed valve is contained in a chamber 34: and beloW the medium speed limie', is seated by the pressure of a spring 3F.

According to my invention, the piston chamber 2l of the split reduction cut-out device It is connected to a passage 3G leading to the seat of the pilot portion slide valve 13, so that when the slide valve is in the usual release position, as shown in the draivin the passage 36 is lapped by the slide va; e, but when the piston ll and slide valve. 13 arrl shifted to the outer or application po ion, the passage 3G is connected to the valve chamber l2.

The passage 3G connected by passage. 5?, pipe 38, and passage 39 in the speed governor., to chamber 34 containing the medium speed valve ln operation, when a train is running above the medium speed limit, the speed governor holds the medium speed valve 33u11- seated, so that the medium speed valve chamber 34 and the split reduction cut-out piston chamber Q1 are connected to the atmosphere, but normally, there is no venting of fluid to the atmosphere, since the piston chamber 2l is not supplied with fluid under pressure from any source.

If aI change in signal indication occurs, as from a high speed to a. medium or loiv speed, the pilot valve piston chamber lO Will be vented to the atmosphere, as in the pending application, here-inbefore referred to, so that the pilot valve piston 11 and slide valve 13 are shifted to brake application position, in Which the brake application is initiated.

In brake application position the pilot valve slide valve 13 uncovers the passage 36 and permits fluid under pressure to flow 'from the valve chamber l2 into passage 3G and then to the split` reduction piston chamber 2l.

Said passage and chamber are vei'ited to the atmosphere through the open medium speed valve in the speed governor', provided the speed of the train exceeds 'the medium speed limit. The vending of fluid from pistou chamber Q1 at the medium speed valve 33 at such a rate that the pressure, in said chamber is prevented from being built up by floiv from chamber l2, and consequently, the piston Q2 and slide valve E24- of the split reduction cut-out device, will not be moved to their inner position against the opposing pressure in valve chamber 23. Thus, above medium. speed, the split reduction cut-out device 4l remains in its outer position, as shown in the drawing, in which position, cavity 25 in the slide valve 24 connects the `passages 26 and QSfrom the first and second reduction reservoirs, resp ictively, so that a. continuous, single stage reduction in brakeA pipe pressure occurs.

if the train is ruiming below the medium speed limit, the speed governor is in such a position, that the medium speed valve 33 is seated by the pressure of the spring 35.

llilith the medium speed'valve seated, if an automatic application of the brakes is initiated, the pilot valve device 2 shifted to its outer position, as hereinbefore described, and permits fluid under pressure from the valve chamber 1Q to flow to passage 36 and to the split reduction cut-out piston chamber #lince the medium speed vaire 33 is noiv closed, the chamber Qland passage 36 are not vented to the atmosphere, and the pressure builds up in piston chamber it, sot-hat the fluid pressure on the opposite sides of the cutout niston 22 become equal and the pressure of spring t0 then shifts the `piston and slide valve 2st to their upper position in which the passages Q6 and 23 are disconnected, with the result, that the brake pipe pressure is reduced in tivo stages, in the manner described in detail in the pending application, hereinbefore referred to.

it is evident, that since fluid under pressure is supplied to the split reduction cutout valve piston chamber 2l onlyT when the f apparatus operates to effect an application of the brakes, that While said chamber is open to the atmosphere through the medium speed valve 33, when the speed of the train exceeds the medium speed limit, there will be no flow of fluid under pressure to trie atmosphere, while the train is running, unless the apparatus is operating to effect an application et the brakes.

Having now described my invention, What I claim as new and desire to secure bylietters Patent, is

1. ln a train control apparatus, the combination with means for effecting an application of the brakes `in two stages, of a valve device operable by fluid under pressure for rendering said means eltective to cau-,1e an agplication ot the brakes in two stag s, means operable when the speed of the train above a predetermined speed limitfor venting fluid from said valve device, and n'ieans operable only upon operation o't the apparatus to effect an application of the brakes for supplying fluid under pressure to said valve device.

2. ln a train control apparatus, the combination with means for effecting an application of the brakes in tivo stages, ot a valve device operable by variati ons in fluid pressure for either rendering` said means effective or inell'ective to cause an application of the brakes in tivo stages, meansoperated according to the speed of the train for venting fluid from said valve device, said means operable only in applying the brakes for supplying fluid under pressure to said valve device.

lll-l lli for either rendering said means effective or ineffective to cause an application of the brakes in two stages, means operated accordin g to the speed of the train and independently of the signal indication for venting` liuid from said valve device, and means operable only when the apparatus operates to eliect an application of the brakes for supplying fluid under pressure to said valve device.

t. In a train control apparatus, the combin ation with meansfor effecting' an application of the brakes in two stages, of a valve device subject en one side to fluid under pressure and operated by supplying` fluid under pressure tothe other side for renderin said means effective to apply the brakes in two stages and operated by venting fluid from said other side for rendering said means ineflective to apply the brakes in two stages, and means operable to initiate an application of the brakes and to supply fiuid under pressure to said other side of said valve device. Y

In a train control apparatus, the coinbination with means for effecting an application ofthe brakes in two stages, of a valve device operated by variations in fiuid pressure for either rendering said means effective or ineffective to cause an application of' tlie brakes in two stages, a speec` Oovernor controlled by tlie speed ofthe train, a valve operated by said governor when the speed of the train is above a predetermined speed .fluid from said valve device,

limit for venting` fluid from said valve device and when the speed is below a predetermined speed limit for preventing the venting oi and means operated when the brakes are. applied for supplying fluid under pressure to said valve device.

6. In a train control apparatus, the combination with an application valve device for initiating,` an application of the brakes, a pilot valve device for controlling the operation of said application valve device, and means for ctlecting an applica-tion of the brakes in two stages, of a valve device operated by variations in fluid pressure for either rendering said means effective or ineffective to cause an application of the brakes in two stages, said pilot valve device having` means for supplyingr fluid under pressure to said valve device.

7. In a train control apparatus, the combination with an application valve device for initiating an application of the brakes, a pilotvalve device for controlling the operation of said application valve device, said means for effecting an application of the brakes in two stages, of a valve device operated by variations in fluid pressure for either rendering said means effective or ineffective 'to cause an application of the brakes in two stages, said pilot valve being adapted to supply fluid under pressure to said valve device when operated to effect the operation of said application valve device.

In testimony whereof I have hereunto set my hand.

CLAUDE A. NELSON. 

